Institute of Archaeology

The impact of evolving of rice systems from China to Southeast Asia

Understanding
the development, diversification and spread of rice agriculture is
central not only to our understanding of the processes of human
population growth, dispersal and formation of civilizations in Asia,
it is also central to reconstructing how past agricultural activities
might have impacted global climate through methane emissions and
deforestation.

Rice
paddies, as artificial tropical wetlands, produce methane. Wet and
irrigated field systems of rice may produce higher yields of grain
but they also produce more methane than dry or rain fed rice. As a
major non-industrial source of methane, rice has been postulated as a
major contributing factor to a rise in global methane levels from
after 5000 BP.

We have recently produced the first
quantitative model of the spread of wet rice agriculture and its
likely contribution atmospheric methane levels alongside that of the
spread of cattle herds. These first models have high levels of
uncertainty due to the very sparse record of high quality
archaeobotanical evidence for rice cultivation, and especially
cultivation methods in southeast Asia (including northeast India and
the southern provinces of China).

As dry rice
systems are not expected to pro­duce much methane, and the recent
high quality archaeobotanical data from a few sites in Thailand point
to dry-farmed rice into the First Millennium BC, it is critical to
gather more empirical data for refining models for the origins and
extent of wet rice farming in prehistoric Southeast Asia, including
the southern provinces of China for which equivalent data for rice
cultivation methods is almost entirely lacking Because irrigated
rices require a substantial capital labour investment in the creation
and maintenance of field systems and irrigation, the development of
such systems is also central to understanding regional social
evolution.

Archaeobotanical
evidence offers a powerful set of tools for not only documenting
where and when rice was cultivated in the past, but how it was
cultivated through the analysis of ecology of associated weed flora
in macro-remains assemblages and phytolith assemblages. We have
pioneered the study archaeological rice weed flora and the
combination of archaeological plant macro-remains and phytoliths in
our recent NERC-supported research in parts of India, Sri Lanka and
China (NE/G005540/1 [Early Rice Project]).

We propose to roll
out this method over a wider geographical and cultural area, as well
refining the approach through some additional modern analogues.
Because current evidence already provides an empirical framework for
the early development of rice cultivation systems in the Yangtze
(especially the Lower Yangtze), between 5000 and 2000 BC, and a firm
basis for the later intensification of rice agriculture in the plains
of northern and eastern India (2000-500 BC), we will now focus our
work on the less known parts of Asia, especially mainland Southeast
Asia and the southern parts of China, as well as further work in the
eastern parts of India.

These regions are central to hypotheses on
the dispersal of rice cultivation, including models linking the
spread of rice to major language families such as Austroasiatic and
Austronesian, and yet a lack systematically-studied evidence for rice
cultivation itself, or evidence as to whether early rice represented
an extension of the alluvial wetland cultivation systems like those
of the Neolithic Yangtze (early subspecies japonica, typical
of many modern temperate japonica) or the development of
upland rainfed systems (the latter typical of many modern tropical
japonica rices), with a secondary later parallel evolution of
irrigated wet rice systems amongst indica rices.

It is also
hypothesized that irrigated rice in mainland southeast Asia was a
later introduced from Indian irrigated traditions different from the
upland rice systems that had diffused from China in the Neolithic.

Related outputs

This is a new research project and details of related outputs will be made available in due course.

Dorian Fuller was one of two invited plenary speakers at the 7th Annual International Rice Genetics symposium, held in the Philippines in November 2013. Read more»